Summary
Definition
History and exam
Key diagnostic factors
- presence of risk factors
- dermatitis
- insomnia, depression, or memory loss
- intermittent stupor
- hallucinations or delirium
- weakness
- peripheral neuropathy
- oppositional hypertonus or myoclonus
- cogwheel rigidity
- primitive reflexes
- ataxia
- nausea, vomiting, or diarrhoea
- glossitis, cheilitis, or stomatitis
Other diagnostic factors
- fatigue
- anxiety or paranoia
- anorexia, weight loss, or cachexia
- headache
- vertigo
- incontinence
- constipation
- heartburn
- angular palpebritis
Risk factors
- malnutrition
- chronic alcohol use disorder
- vitamin B2 (riboflavin) deficiency
- vitamin B6 (pyridoxine) deficiency
- malabsorption
- eating disorders
- Hartnup's disease
- carcinoid syndrome
- antituberculous drugs
- Crohn's disease
- HIV infection
- copper deficiency
- certain drugs
- pregnancy and lactation
- age >65 years
- Alzheimer's dementia
- Parkinson's disease
Diagnostic investigations
1st investigations to order
- serum tryptophan
- urinary N-methylnicotinamide
- urinary N-methyl-2-pyridone-5-carboxamide
- urinary 2-pyridone/N-methylnicotinamide ratio
- skin biopsy
- photosensitivity testing
- FBC
- serum albumin
- serum protein
- LFTs
- gamma-GT
Investigations to consider
- serum total iron
- iron-binding capacity
- ferritin
- transketolase activity
- thiamine pyrophosphate (TPP)
- riboflavin coefficient
- serum pyridoxal-5-phosphate
- serum cyanocobalamin
- serum folic acid
- red cell folic acid
- stool examination
- neutral aminoaciduria
- serum serotonin
- platelet serotonin
- urinary 5-hydroxyindoleacetic acid
- HIV antibodies
- mental-state examination
- ECG
Treatment algorithm
Contributors
Authors
Senior Research Specialist
Centre for the Study of the Social and Environmental Determinants of Nutrition
Population Health, Health Systems and Innovation
HSRC
Cape Town
South Africa
Disclosures
WP declares that she has no competing interests.
Professor
School of Public Health
University of the Western Cape
Cape Town
South Africa
Disclosures
ZJM declares that she has no competing interests.
Professor Emeritus
Stellenbosch University
Professor Extraordinaire
University of Limpopo
South Africa
Disclosures
DL declares that he has no competing interests.
Dr Whadi-ah Parker, Dr Zandile J Mchiza, and Dr Demetre Labadarios would like to gratefully acknowledge Dr Nelia Patricia Steyn, a previous contributor, as well as Miss Nophiwe Job, Ms Nwabisa Tshefu, and Mr Machoene Derrick Sekgala for their contributions to this topic. NPS, NJ, NT, and MDS declare that they have no competing interests.
Peer reviewers
Emeritus Professor of Clinical Chemistry
University of Liverpool
UK
Disclosures
AS declares that he has no competing interests.
CBNS
Queens College
City University of New York
NY
Disclosures
AM declares that he has no competing interests.
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